Glass grinding and polishing machine



June 26, 1928.

J. CLETON, JR

GLASS GRINDING AND POLISHING MACHINE Sheets-Sheet. 1

I Jpj/SQ Filed May 6, 1927 June 26, 1928 1,674,888

J. CLETON. JR

GLASS GRINDING AND POLISHING MACHINE yd May 16, 1927 2 Sheets-Sheet 2 //V/ E/l/70/? I Patented June- 25, 1928..

; enirr.n STATES JOI-IANNES CLETON, JR., OF ROTTERDAM, NETHERLANDS.

v GLASS GRINDING AND POLISHING, MACHINE.

Application filed May l6, 1927, Serial No. 191,869, and in the Netherlands October 16, 1924. y

This invention relates to a machine for simultaneously grinding or polishing a number of grooves located adjacent each other, in plates of glass, marble and'like materials.

Plates of this kind are used for instance in meat slicing machines; the grooves extend from one of the edges of the plate over a part of its length and prevent themeat to be sliced slipping under the pressure of the knife during the cutting movement.

Up to the present the grooves were generally'made by hand and one after the other. The plate to be ground was pressed against a rotating grinding disc and reciprocated until the desired depth of the groove was obtained.

It will be clear that this method is very uneconomical and ineflicient for making a great number of grooves, especially because it is necessary that they have all exactly the same depth so that a sufficiently sharp edge remains between two adjacent grooves.

The object of the present invention is to provide a machine for automatically grinding such plates. The machine has a plurality of grinding discs arranged upon a rotatable shaft, a supporting table for the plate to be worked, arranged below the disc shaft in a plane parallel to the disk shaft and adjustable in vertical direction, and a driving mechanism adapted to impart a reciprocating motion to the table in a horizontal plane along the discs and constructed in such a way that during the working stroke the desired rate of feed is obtained, but a greater speed during the retrogressive movement. I

Machines having a rotating shaft with a plurality of grinding discs fixed thereto are known in themselves. In the known machines of this kind the piece of work may also be fixed upon a horizontally moving table. These machines are used for providing glass plates with bevelled edges, or for grinding profiles into marble blocks. However for the purpose as described above these known machines cannot efiiciently be used.

In grinding fine grooves positioned closely to one another, one has to regulate the feeding speed in such a. manner that the discs with the carborundum powder supplied thereto do not shatter or otherwise remove the edges between the grooves.

Preferably metal discs are used, as it is found in practice that these discs, with ad dition of water and carborundum powder have a larger capacity than carborundum' discs. The latter have the drawback that the feeding speed cannot be increasedwithout shattering or removing the edges between the grooves.

According to the invention the driving mechanism of the table may comprise a horizontal disc, rotated about a vertical axis and provided with a. curved cam track cooperatingwvith a pin projecting from the table.

In the accompanying drawings a machine according to the invention is illustrated by way of example.

Fig. 1 is a front elevation of the machine,

Fig. 2 is an end elevation of the same,

Fig. 3 is a detail on larger scale,

Figs. 4 and 5 are a front elevation and a plan view respectively of a glass plate with grooves.

The table 1 is mounted in the frame 2 movable in a horizontal plane. The frame 2 itself may be adjusted in a vertical direction by means of a threaded rod 3, bevel gear wheels 4 and a handwheel 5. The table 1, supporting the plate to be ground, is driven from the shaft 6. Upon said shaft is first fixed the driving pulley 7, secondly a pinion 8 meshing with a gear wheel 9. To the shaft of said gearwheel 9 is attached a pulley 10, driving by means of the pulley 11 a wormshaft 12. The worm 13 upon said shaft is meshing with a worm-wheel 14, on the shaft of which is fixed a disc 15, provided with a curved groove or track 16. In this track fits a pin 17, fixed to the table 1. In this way the rotating movement of the worm-wheel 14 is transformed into a reciprocating movement of the table. The curved path 16 is chosen in such a way that a slow feeding movement and an accelerated return movement is obtained.

This construction has the advantage, that by varying the form of the track 16 one may adjust the speed of the table both at the forward stroke and the return stroke, also the pin, clearing the bottom of the groove as shown in Fig. 1, and bearing only against the propelling sides of the groove, is freed from vertical vibrations arising in the disk 15 from the movements of its driving mechanism, and which would otherwise be communicated through the pin to the table, jarring the latter so as to cause damage to the edges being ground between the grooves.

Above the table and parallel with it, is

mounted the shaft '18, supported in its bearings 19'and driven by the pulley 20. Upon this shaft the grinding discs 21 are mounted.

If the grooves are to be ground as illustrated in Figures 4 and 5 ofthe drawings the discs have the profile 22. The depth of the grooves may be adjusted by means of the wshee n ow rin r n th 12- porting table 1. T he depth may be measured in supplying marksupon the h andwheel 5, so

.that a -certain angle of rotation corresponds with a certain displacement of the table.

In moving the table up and. down the wormshaft 12 also moves, whereas the shaft of the g eaiwheel 9 and pulley 1O is stationary. Itvvill be advisablefor this reason to providethe belt over the pulleys 10 and 11 swithqa device for keeping thebelt stretched. The machine may be also employed to 20 polish by means of discs of stone, leather. or

felt.

I claim:

A machine for grinding parallel grooves partway across'a plate, and preserving accurately straight and keen edges between the grooves and surface of the plate, comprising a horizontal shaft with parallel vertical grinding disks smounted to rotate therewith,

a'hori z ontal table arranged below and having a travel inaplane tangentto said disks,

toward the disks and rapidly return the same, and a projection from the table engagingi only thepropelling Walls of said groove, to avoid as far as possible'the vibration of the tableby its reciprocating means. i

:In testimony whereof I afliX my signature. Y I a JQHANNES J13; 

